Relay.



C. H. ZEERDT.

RELAY APPLXQATION man FEB. 20. 1911 1,284,026. Patent-6d Nov. 5, 195:8.

WITNESSES iNVENTQF? UNTTED STATES PATENT f CONRAD H. ZIERDT, 0F EDGEWOODBQROUGH, PENNSYLVANIA, ASSIGNDR. TO THE UNION SWITCH & SIGNAL COMPANY,OF SWISSVALE, PEIQ'NSYZ'LVANIEL, A CORPO- RATION OF PENNSYLVANIA.

Specification. of Letters Patent.

RELAY.

Patented Nov. 5, 11931 8.

Application filed February 20, 1917. Serial No. 149.78%.

' Edgewood borough, in the county of Allegheny and State ofPennsylvania, have in vented certain new and useful Improvements inRelays, of which the following is a specification. y

This invention relates to relays, and more particularly to a vane relaywhich is responsive for contact operation only to alternating current ofa frequency above a predetermined value. l

In the accompanying drawings, Figure l is a view showing in frontelevation one form'of relay embodying my inventiont' Fig. 2 is a viewshowing in top plan the relay shown in Fig. 1. Fig. 3 is a transversesectional view taken on the line III-HI of Fig. 2.

Similar'reference characters refer to similar parts in each of theseveral views.

Referring now to the drawing, the relay in the form here shown comprisesa laminated soft iron core 0, and avane V of non-magnetizableelectro-cond'uctive mate- .rial such as aluminum. The core C issubstantially C-shaped as shown in Fig. 2, and the vane V is pivoted atX to swing in the air gap between the two confronting ends of the core.The main body of the core is of one thickness, as shown at the righthand end of Fig. 3, but the two confronting legs R, R are of a greaterthickness owing to additional laminations K. These laminations areseparated from the other or main laminations by several laminations L ofcopper or other non-magnetic electro-conductive material.

The confronting ends of the core legs R, R are each provided with threepoles P, P and P Poles P and P are formed by cutting back'thelaminations in the main body of the core at 2, this out being considerably below the middleo'f'the main core body so. that pole P isconsiderably larger than pole P. copper ferrule or shading band '15, afew of the laminations at the top of the main core body being cut backso that this ferrule fits between the main core body and the lowestofthe plates L. Pole P is formed by the additional laminations K asshown in Fig.1. Pole P is considerably larger than pole P, so that polePf has consider- Pole P is provided with a' ably less reluctance thanpole P for a rea- I son which will appear hereinafter.

Each core leg R is provided with an energizing coil W, which coils are,as here shown, connected in series. The vane V is provided with acontact bar Y which co acts with fixed contact members Y. The vane isbiased to swing around its pivotal point X in clockwise direction fromthe position shown in Fig. 3, but is at times swung in opposition tosuch bias to the position in which it is shown in Fig. 3, in

. which position the contact members Y are bridged by bar Y so that thecontact is then closed.

The operation of the relay is as follows: When the coils N, W aretraversed by alternating current, a magnetic flux is generated in thecore C, which, by virtue of the corn struction of the core ends, dividesinto three separate paths when crossing the air gap between the coreends to thread the vane V. One magnetic path is through pole P, thesecond through pole P and the third through pole P and the copperlaminations L. The flux traversing pole P combines with that of pole Pto form a rotating magnetic field which tends to force the vane Vupwardly, this rotating field being due to the shading band E on pole P.In a similar manner the flux traversing pole P and the copperlaminations L combines with that passing through pole P'to form a secondrotating magnetic field which, however, tends to force the vanedownwardly instead of upwardly. Obviously, when the two rotatingmagnetic fields are of equal strength, no torque will be exerted on thevane by the core C, but when either of the fields dominates, such fieldwill tend to move the vane in its corresponding direction. In thisinstance, the pole P being much larger than pole P, the downwardtendency would a lways dominate were it not for the choking effectproducedby the copper laminations L. lVhcn copperv is placed within analternating magnetic field so that the flux passes directly through thecopper, currents are induced therein which in turn generate-a countermagneto-motive force tending to reduce the flux traversing the copper.This action of the induced currents increases in direci proportion tothe frequency of the alternating magnetic field, which frequency ifsuffi ciemly increased would ultimately result in I vention, w 49changes and modificatlorls may be made if, pole P and that by properlyproportionmg the copper laminations the effects of the;

two rotating magnetic fields upon the vane V will be neutralized whenthe coils V, \V.

are traversed by alternating current of a to predetermined frequency, sothat the vane will be unalfected by such fields. If, however, thefrequency of the current supplied to the coils isincreased to a certainhigher frequency the rotating inagnetic fieldpro- 1-.5 duced by poles Pand P will dominate to such extent as to 'force the vane upqwardly tocause downward movement of t e Contact bar 1. Such position of thecontact bar maintained as long as the coils are supplied go withalternating current at or greater than this latter frequency. However,when the flow of current through the coils is discontinued or when thefrequency of such current is less than this predetermined fre- 2,5quency, vane V is released to allow the contact bar Y to move away fromcontacts Y.

From the foregoing it is manifest that I provide a relay which isselective as to requency for contact operation, and that such selectionis obtained by a single core and a single vane. Obviously. such avsimplified construction of relay permits the same to be operated on aminimum amount of current, this being a highly desirable fear ture es)eciallv whena relay is controlled i5 from a track circuit in railwaysignaling.

Although I havev shown and describedv only one form of relay embodyingmy init is understood that various therein within the scope of theappended claims without departing from the spirit and scope of myinvention.

Having thus described my invent-ion, what at I claim is:

1. A, relay comprising a magnetizing coil, a core having each enddivided to provide two outer poles and an intermediate pole, the outerpoles being of different reluctance,

so ashading band surrounding said intermediate pole to produce inconjunction with the two outer poles two rotating magnetic fields ofopposite directions. means for equalizing the effect of said rotatingmag netic fields when said coil is energized with alternating current ofa predetermined frequency and for causing one rotating magnetic field todominate when said coil is energized with current above said predetereamined frequency. and a vane affected in opposite directions by saidmagnetic fields.

2. A relay comprising a magnetizing coil, a core. a shading bandsurrounding an intermediate portion of an end of said core as to producetwo rotating magnetic fields in 'is energized with current of apredetermined frequency and for causing the effect of one of saidrotating magnetic fields todommate when said coil is energized withcurrent above said prcdetern'iined,frequency, and a vane oppositelyaffected by said magnetic fields.

3. A relay comprising a magnetizing coil, a core. a shading bandsurrounding an intermediate section of an end of said core, toproducetwo rotating magnetic fields in opposite directions, a chokingmember arranged within. one of said magnetic fields, and a vaneoppositely affected by said mag nctic fields.

4. A relay comprising a magnetizing coil, a core. a shading bandsurrounding an interi'rmdiate section of an end of said core, to producetwo rotating magnetic fields in o posite directions, means for increasint e counter-magneto-motive force of one 0 said magnetic fields to causea weaker rotating field in one direction than in the other when saidcoil is energized with current above a predctern'iined frequency, and toequalize said rotating magnetic fields wheirsaid coil is energized withcurrent of said predetermined frequency. and a vane mounted for movementbetween said opposed ends and oppositely affected by said rotatingmagnetic fields.

5. A relay omprising a vane, contacts controlled by said vane, a core, amagnetizing coil for said core, shading bands surrounding portions ofthe opposite ends of said core for producing two rotating magneticfields in opposite direct-ions and of unequal strength when said coil istraversed by alternating current of one frequency, but of equal strengthwhen said coil is traversed by alternating current of another frequency.

6. A relay comprising a coil, a core having the ends thereof arranged ino posed relation, each of said ends being ormed with three poles, ashading band surrounding the middle pole of each set to form tworotating magnetic fields in o posite directions and of different strengt5, means interposed between two poles of each set for equalizing saidrotating magnetic fields when said coil is traversed by alternatingcurrent of predetermined frequency and for increasing thecounter-magneto-motive force of the corresponding magnetic circuit tocause the other rotating magnetic field to become dominant when saidcoilis traversed by alternating current above a predetermined frequency,and a vane oppositolyaffec'ted by said rotatingmagnetic fields.

'7. A relay comprising a laminated C- shaped core. a shading band for'each end of the core and interposed. between the lamimember mounted tomove be.

nations of said core to d V1519 a plurality of polss of ilifi'eyent aslaminations interposed between said poles, a non-magnetic electro-c nQween th of said core and contacts 20mm said member.

